1. Field of the Invention
The present invention relates to a method and apparatus for searching for a recordable area in which real time data can be recorded from an information recording medium having at least one empty area in a dispersed state, and a method and apparatus for testing an arrangement of recorded areas on the information recording medium in which the real time data has been recorded.
2. Description of the Related Art
An exemplary information recording medium having a sector structure is an optical disc. Owing to the recent increase in recording density and memory capacity of optical discs, the application field thereof is expanding. Optical discs are used, for example, for recording real time data such as video data or audio data.
On an optical disc, defect sectors and areas in which data has been recorded (recorded areas) may exist. For additionally recording data, a skip recording system is proposed, by which recording is performed while skipping such sectors and areas (see, for example, Japanese Patent No. 3098237, FIG. 1).
An optical disc apparatus reproduces video and audio by temporarily accumulating data which is read from an optical disc in a buffer and decoding the accumulated data sequentially. When the data accumulated in the buffer is used up, reproduction of video and audio stops. In order to realize uninterrupted reproduction (seamless reproduction), it is necessary to input data newly read from the optical disc before the data accumulated in the buffer is used up.
With the above-mentioned skip recording system, areas in which real time data has been recorded are located in a dispersed manner. In the case where the areas in which real time data has been recorded discontinuously and dispersedly are concentrated in a specific region, or the length of the interval between dispersed areas in which data has been recorded is excessively long, undesirable phenomena such that reproduction of video is temporarily stopped during real time data reproduction occur. With the above-mentioned skip recording system, it is difficult to realize uninterrupted reproduction of real time data.